Aerotecnica Missili & Spazio最新文献

The rise of the “New Space Economy” has expanded access to low-Earth orbits for commercial, non-profit, and educational entities. This has driven significant growth in the small satellite market, offering a low-cost solution for various missions. Autonomous proximity operation systems for small satellites are actively studied for their wide-ranging applications. Experimental Rendezvous in Microgravity Environment Study (ERMES) is a student project, which aimed at testing an autonomous docking manoeuvre between two free-flying CubeSats mock-ups in a reduced gravity environment. The manoeuvre is characterized by an active Chaser and cooperative Target approach. In particular, the Chaser is equipped with a cold gas propulsive system based on expendable (hbox {CO}_{2}) cartridges for three-dimensional manoeuvering, whereas the Target has a set of reaction wheels for attitude control. The magnetic post-manoeuvre connection is achieved thanks to a dedicated miniaturized docking interface. Moreover, the reduced gravity conditions have been achieved by participating in the European Space Agency (ESA) (79^{th}) Parabolic Flight Campaign thanks to the selection in the ESA Fly Your Thesis! Programme 2022 (FYT).

This article provides an overview of the ERMES experiment, discussing its main objectives and key design solutions. It first describes the design of the Guidance Navigation and Control subsystems of the two mock-ups, then discusses the results of the parabolic flight campaign, and finally focuses on the analysis of a specific parabolic test, where the Chaser was able to dock by recovering a high overall misalignment.

Numerical simulation is a feasible and effective way to investigate the ballistic impact behavior of material. In this research, the numerical simulations of ballistic impact behavior of 2024-T351 Aluminum plates with different thicknesses struck by blunt projectiles are conducted via two numerical approaches, including a data-driven approach using the commercial software ABAQUS/Explicit and MAT224 material model using the commercial software LS-DYNA, are employed to analyze the impact response of 2024-T351 Aluminum plates, respectively. Within the data-driven approach, an enhanced rate-dependent data-driven constitutive model is utilized to describe the mechanical response, where the classical Johnson–Cook fracture criterion is employed to characterize the fracture behavior of the materials during impact simulations. Finally, the relationship between residual velocity and impact velocity, ballistic limit velocities, strain, local displacement, and penetration process are comprehensively investigated to make a detailed comparison between these two numerical approaches. It is found that the data-driven approach provides better accuracy in predicting ballistic limit velocities. Additionally, the data-driven approach differs from the MAT224 material model in the numerical simulation of target plate penetration. This research is to provide instructions for the choice of a numerical approach to the impact simulation of 2024-T351 aluminum.

Monitoring of the near-Earth space environment has become more and more important in recent times. The constantly increasing amount of space debris is a major threat for space activities and an exhaustive knowledge about the space objects population is of primary importance for civil and military applications. The surveillance of the space surrounding the Earth is achieved by means of sensors based on different technologies. Passive optical observations using ground telescopes are usually employed to track space objects in high altitude orbits. The obtained measurements are sparse, and their arcs are very short. The computation of the orbit based on these observations is challenging and several methods have been proposed. One of the known approaches relies on an optimization scheme of the classical boundary value problem. However, in the latter, the object motion is described by a Keplerian orbit without considering additional perturbations. In this novel approach, orbital perturbations are introduced in the computation procedure using a shooting model. The improved algorithm is applied to simulated observations of objects in the geostationary region under the influence of solar radiation pressure. The measured arcs are separated by intervals of one or more orbit revolutions. The performance of the proposed method is evaluated in terms of accuracy considering different levels of perturbation.

Sun sensors are widely utilized in satellite attitude determination, particularly within Attitude Determination and Control Systems (ADCS), where accurate characterization of the satellite’s orientation stability is crucial. This study aims to qualify sun sensors for new applications, focusing on their positioning and inclination to satisfy mission-specific requirements. The operational environment involves a Polar Satellite Launch Vehicle (PSLV) launcher, with dynamic loads from random vibrations being the predominant stress factor. To align with the ADCS mission requirements of ALSAT 1B observation satellite, the position and inclination angle of the sun sensors were modified, ranging from 70° to 50°. Through a combination of simulations and experimental validation, it was observed that the sun sensors exhibited significant responses due to their location on the satellite. However, subsequent verification procedures revealed no damage to the sensor modules, demonstrating their robustness under these conditions. The results confirm that the sun sensors are adequately qualified for flight, ensuring reliable performance without the risk of failure.

Aero-acoustic analysis was conducted on a weapons bay numerical model with doors, incorporating radar cross section reduction features. The effect of the angle of attack on the aero-acoustic response of the cavity was analysed at Mach numbers of 0.85 and 1.20. It was found that incidence influenced both mean-flow features and acoustic response. Further, linear and angular accelerations induced by the flow on the bay doors revealed potential adverse fluid–structure coupling when the results were compared with modal analysis. Again, the angle of attack did influence the aeroacoustic effects on the cavity door structure.

This article studies a new, fully digital approach towards General Aviation (GA) aircraft certification. Model-Based Systems Engineering (MBSE) techniques will be used to develop a Digital Certification Pipeline (DCP) to support both conventional and innovative, unconventional aircraft configurations to be certified under the European Union Aviation Safety Agency (EASA) Certification Specifications CS-23, including electric/hybrid propulsion systems (EHPS) and distributed propulsion (DP) configurations. The DCP will produce all the EASA-required certification artifacts, transitioning from the past document-based paradigm to a more effective, less error-prone, digital certification process. All certification artefacts will be centrally managed, with only minor corrections needed before the final submission to the Certification Agency. The DCP will represent an easy-to-use, effective tool to reduce certification time and costs, enabling aircraft manufacturers to introduce new aircraft models with high safety standards for the future of the GA market. Future developments are discussed at the end of the article, evaluating the possible extension of the paradigm used to CS-25.

The 21st century has witnessed an expansion of space operations throughout the Earth–Moon system and the wider Solar System with the introduction of new space-faring countries, decreasing costs of space access, and advances in space system technologies. Many countries are endeavoring to move outside geosynchronous orbit to pursue missions in cislunar space and lunar orbit, as well as on the lunar surface, with invigorated U.S., Chinese, and Russian lunar mission initiatives being principle examples. Coalescing international efforts to return to the Moon may result in not only the pursuance of short-duration crewed lunar missions, but also the attainment of the first extraterrestrial human settlement(s) and the establishment of a permanent lunar base. Site selection for short-duration soft landings and the construction of basing/infrastructure will become a critical function to enhance mission assurance and operational safety. In this paper, an atlas of human activity on the lunar surface is presented featuring a concise mapping of locations associated with historical lunar impactor and soft-landing sites and proposed future basing and infrastructure reports. The atlas seeks to enable a holistic depiction of lunar surface activity to gain insight into where future lunar bases may be located and establish historical patterns of proposed basing.

This paper presents the results of the suborbital flight of the Mini-IRENE Flight Experiment (MIFE), flight demonstrator of the IRENE (Italian Re-Entry NacellE) technology, a variable-geometry re-entry capsule for Low-Earth Orbit payloads. A capsule equipped with a mechanically deployable heat shield was successfully launched with a VSB-30 suborbital rocket from the Esrange base in Sweden, achieving an apogee of 260 km, a peak deceleration of 12 g and surviving the landing with successful retrieval. A huge set of telemetry data was acquired, including GPS, attitude, temperature, pressure, acceleration measurements. The capsule showed aerodynamic stability at all flight regimes. The peaks of deceleration and dynamic pressure were higher than predicted, as if drag was lower than expected during supersonic descent, but the capsule successfully survived landing, validating the mechanical resistance of the design even after ground impact.